ornithology exam 3

definitions for song types, repertoire, countersinging, dialects, solicit a copulation, calls, contact calls, alarm calls, mobbing calls, mob, begging calls, non-vocal sounds Song types: variants of a typical song

ly

Repertoire: different song types an individual bird can sing

countersinging: strategically matching or mismatching song types can either escalate or defuse a social altercation

dialects: regional variations in the songs of the same species

solicit a copulation: a signal emitted by a female bird inviting a male to mount and mate.

calls: short, simple, generally for other purposes than courtship or territorially

contact calls: are the most abundant bird sounds we hear, other than songs in spring time, generally very short, simple, and species specific. Help maintain social bonds, keep track of other flock members (such as during nocturnal flight), and sometimes even serve as warnings when the call stops.

alarm calls: often recognized across species boundaries, calls tend to have similar structures: high-pitched, thin, whistly, and fading in and out. These sounds are difficult for a predator to localize

mobbing calls: quite similar across species, but have a very different acoustic structure: they are loud, broadband (hoarse), harsh, abrupt, and repeated. They are easy to recognize and draw attention to a known predator.

mob: harassing predators from safe positions.

begging calls: generally given by nestlings, and tend to be loud and harsh. They largely appear to signal need and the nestling’s energetics.

non-vocal sounds: many bird species produce sounds for courtship, territoriality, alarm, or other communication purposes via other means, might evolve to communicate specific information over different (usually longer) distances than a bird can produce vocally, such as downy woodpecker drumming

definitions for syrinx, sensitive period, subsong, plastic song, crystalized song, open-ended learners

syrinx: organ birds use to produce vocal sound, similar to a human larynx, positioned much lower along the trachea, where it splits into the two major bronchi that enter the lungs

sensitive period: listening period to learn and memorize birdsong, happens within their first two months of life.

subsong: babbling by songbirds that happens after or near the end of the sensitive period, songbirds start exercising the motor and neural pathways needed to produce song.

plastic song: As young songbirds age, their initial subsongs develop through constant practice into more confident songs that begin to resemble the species-typical songs

crystalized song: when practice is complete, the bird can now produce that song at will with high consistency, for the rest of its life.

open-ended learners: species that are not restricted to learning early in life during sensitive and practice periods and can learn and practice new song types throughout life

Explain song-control centers

form in the brain and includes two main pathways, one each for the physical and cognitive aspects of producing songs. the size of these specific brain tissues correlates with complexity of song and song-learning (e.g. larger in singing males than non-singing females). These brain regions often undergo seasonal regression, just like reproductive tissues

How do bird songs generally differ from calls (acoustically and in

function)?

Songs are generally longer, more complex, and feature rhythmic notes or syllables, while calls are usually short and simple, consisting of brief, uncomplicated notes or sounds. Songs are primarily used for mate attraction and territory defense, often produced by males. Calls are used for social communication, such as alarm calls, contact calls, and begging calls.

Do different species tend to have different songs? Why or why not? and Describes some ways that different individuals within one species may

have different songs

songs vary between species for a multitude of reasons, such as to ensure they know what species is which, and within a species variation arises from different song types, individual repertories, and regional dialects often influenced by genetics, environment, and social learning.

Explain how songs can be used in territorial and courtship contexts,

using the terms “countersinging” and “copulation solicitation” in your

answer.

songs cab be used in territorial defense such as countersinging, where males may exchange songs to establish or maintain their boundaries. In courtship contexts, females use copulation solicitation to indicate their readiness to mate, usually in response to a male.

Briefly explain the general acoustic structure and behavioral function of

each of the following types of calls: contact, alarm, mobbing, and

begging

contact calls: most abundant bird sounds we hear, other than songs in spring time, generally very short, simple, and species specific. Help maintain social bonds, keep track of other flock members (such as during nocturnal flight), and sometimes even serve as warnings when the call stops.

alarm: often recognized across species boundaries, calls tend to have similar structures: high-pitched, thin, whistly, and fading in and out. These sounds are difficult for a predator to localize

mob: quite similar across species, but have a very different acoustic structure: they are loud, broadband (hoarse), harsh, abrupt, and repeated. They are easy to recognize and draw attention to a known predator.

begging: generally given by nestlings, and tend to be loud and harsh. They largely appear to signal need and the nestling’s energetics.

What is a non-vocal sound, and what are some examples?

non-vocal sounds: many bird species produce sounds for courtship, territoriality, alarm, or other communication purposes via other means, might evolve to communicate specific information over different (usually longer) distances than a bird can produce vocally, such as downy woodpecker drumming

What is the syrinx, and where is it found in the body of songbirds? Note

how this placement is significant in terms of ability to produce multiple

sounds. Do all birds have the same syrinx structure (or a syrinx at all)?

Birds produce vocal sounds using the syrinx, which works similarly to the human larynx (our “voice box) Our larynx sits at the upper end of our trachea (windpipe), close to our mouth, a bird’s syrinx positioned much lower along the trachea, where it splits into the two major bronchi that enter the lungs. because of it’s placement, both sides of the syrinx can be used independently, creating two different sounds. some birds have different syrinx structures, and some birds, such as black vultures do not have one at all.

Briefly compare how suboscines vs. oscines know what to sing. Which

types of birds are well known for learning their songs?

oscines, or songbirds have more complex syrinx and musculature that allows for intricate song learning. suboscines have simpler syrinx structures, resulting in less complex vocalizations.

What are the four basic stages of song learning (as discussed in

lecture)? Describe what tends to happen in each. What is different

about open-ended learners?

1. sensitive period: memorize all the templates for adult songs they may need by listening to nearby adults (tutors) within their first ~2 months of life.

2. subsong: towards the end of the sensitive period, song birds start to exercise motor an neural pathways and produce babbling song

3. plastic song/rehearsing: their initial subsongs develop through constant practice into more confident songs that begin to resemble the species- typical songs

4. crystallization: the bird can now produce that song at will with high consistency, for the rest of its life.

5. Open ending learners: species that are not restricted to learning early in life during sensitive and practice periods and can learn and practice new song types throughout life

What are the two processes run by the “song-control centers”?

two pathways for the physical and cognitive aspects of producing songs, the size of these specific brain tissues correlates with complexity of song and song-learning, these brain regions often undergo seasonal regression, just like reproductive tissues

functions for bird nests?

A place to hold and gather eggs, have temperature control and shelter for eggs and nestlings, help with avoiding predators, and reinforcing the social bond between the pair during builidng.

explain all types of nests

Scrape: shallow scrape in the substrate to create a depression, maybe a few rocks or twigs, common in shorebirds and ground nesters

Platform: shallow depression on top of a mound or platform of nesting material

cup nests: deep-cup shaped impressions

statant cups: built on a supporting surface

pensile cups: hang under their supports

Pendulous cups: deep and dangling

adherent cups: stuck to a vertical surface

dome cups: statant cups with a roof

globular nests: fully enclosed and have unexpected side entrances

cavity nests: in cavities

mound nests: literal mounds of material with hidden chambers inside

How do birds build their nest?

males, females or both may build nests depending on the species, what type of nest and the basics of how are genetically determined and match the species’ ecology, bird appear to learn in nest building.

Recognize major egg structures and very briefly describe the function of

each.

yolk: first piece of the egg developed, filled with fats and proteins as food for the developing embryo

Germinal spot: where the embryo sits and develops, visible as a pale spot on the yolk

vitelline membrane: separates the egg yolk from the albumen and holds the yolk in place

albumen: egg white, developing embryo’s main protection, and a source of water and protein

Chalazae: stringy protein threads that help suspend the yolk in the egg

shell: hard outer calcium-rich membrane that encloses the albumen, allows for gas and water exchange

chorioallantoic membrane: connects the chick’s organs to the yolk and to storage spaces for waste.

Are eggs more likely to be plain-colored in protected nests or open

nests (like scrapes)?

in scrapes, eggs are more likely to be cryptically colored such as brown or earth tones to camouflage against the ground and avoid predators.

In protected nests, eggs are more likely to be plain colored, and white for easy visibility for the parents

Describe the process of incubation. Why do many birds wait to start

incubation until the clutch is complete? Why do other birds not wait?

incubation is behaviors parent birds use to keep their eggs at optimal temps for development, females will make a a bare brood patch by losing feathers on their beast and belly feathers to keep the eggs at temp for development. Many birds wait until the clutch is complete to start incubation so they hatch synchronously. Other birds do not wait, and do asynchronous hatching to ensure one larger nestling.

Compare general patterns between altricial and precocial nestlings,

such as incubation time, time in nest (if any), types of species, size of

yolk, independence of nestlings

Altricial: short incubation, long time spent in the nest, types of species include songbirds, woodpeckers, hummingbirds, and birds of prey. Yolk sizes are smaller and are fully dependent on parents for survival.

Precocial: Long incubation time, almost none to no time spent in nest after hatching, species include, waterfowl, shorebirds, Galliformes, and ratites, The yolks are larger and nestlings are mostly or fully independent

terms for gape, crop milk, and egg tooth

Gape: mouth of birds, usually colorful intended to beg for food

egg tooth: developed on their bill prior to hatching to help break the shell

crop milk: esophagel substance fed from parents to offspring

terms for Crypsis, Background-matching, disruptive coloration, countershading, monochromatic, sexual dichromatism

crypsis: blending in with the background

Background-matching: colors of feathers match bird’s background

disruptive coloration: involves streaks, stripes, or patches that visually break up the solid outline of the bird to make it harder to distinguish on a similarly mixed background.

countershading: broad coloration pattern featuring darker colors on the dorsal side (top) and lighter on the ventral (bottom). Countershaded coloration interacts with light and the background to make the animal less clearly visible from either top, bottom, or side

monochromatic: one base color

sexual dichromatism: difference in plumage coloration between the two sexes, often with bright males, and dull, cryptic females.

Terms for pigments, melanin, carotenoid, Porphyrins, turacoverdin,

pigments: molecules that absorb some wavelengths of visible light

melanin: synthesized within a bird’s cells, shades of earth tones, strengthen the structure their deposited in.

carotenoid: not synthesized by birds, acquired from diet, usually modified, pinks, reds, yellows, oranges, carotenoid-based ornamental pigments reflect the bird’s health and general fitness.

porphyrins: can be synthesized by birds, appear to enhance melanin-based coloration in owls, galliforms, pigeons, and eggshells, glow in UV lights.

turacoverdin: copper-based type of porphyrin, among the only known green pigment in birds.

terms for structural coloration, coherent scattering, spongey layer, structural blue, Iirdescence, structural white

structural coloration: keratin-based structure of a feather itself bends light to reflect just some wavelengths, other light is transmitted through

coherent scattering: some wavelengths of light (e.g. blue) are reflected with their waves in sync (overlapping), enhances the brightness and purity of the color

spongey layer: organized air bubbles in the keratin structure of the feather that causes coherent scattering

structural blue: organized air bubbles in the keratin structure of the feather cause coherent scattering, reflects and enhances just blue light, layer of dark melanin pigment under the spongey layer prevents interference from other colors of light

Iridescence: one or more organized, precisely structured layers of keratin and melanin cause coherent scattering, one or more wavelength (color) of light is reflected by each layer, each color is reflected at a slightly different angle so, the color we perceive changes as we look at these feathers from different angles

structural white: Randomly scattered air bubbles in the keratin cause disordered reflectance, enhancement, and interference across all wavelengths of light (which together form white). Unpigmented feathers generally appear white due to this incoherent scattering

terms for migration, migratory restlessness

migration: a yearly two-way trip between breeding and wintering sites.

migratory restlessness: once migratory behavior begins, birds can’t sit still.

terms for dispersal, local movements, residents, obligate migrants, facultative migrants, partial migrant, leapfrog migration, irruptive movements, staging areas, stopover sites, migratory fallout, migratory bottleneck, and flyways

dispersal: one-time movement away from the location a bird is raised or has previously bred

local movements: the routes birds take on a frequent or daily basis for activities like foraging and roosting

residents: Bird populations that do not exhibit any migratory behavior

Obligate migrants: classic pattern of predictable twice-annual movements between winter and breeding grounds

Facultative migrants: may or may not migrate, will do “normal” migration some years in years with favorable food supplies, may will stay in their breeding grounds through winter, or may migrate partway

Partial migrant: within one single population, some individuals are obligate migrants, while others are facultative

Leapfrog migration: some populations within a species migrate right past other populations, “leaping” over them.

Nomadic species: move unpredictably according to the availability of food, sometimes breeding at very different times and places between years.

irruptive movements: mass southward movements of arctic/boreal populations

staging areas: locations with long, extended (multi-day) visits

Stopover sites: locations with shorter visits (e.g. overnight, or until weather improves)

migratory fallout: massive numbers of birds congregate at a stopover site, exhausted

migratory bottleneck: large numbers of migratory birds close together because of geography, “funneling” species close together

flyways: preferred routes to major breeding/wintering grounds, bird migratory paths

How do birds know when to start migrating? What kinds of information

do they use?

birds know when to start migrating due to their internal biological clock, internal calendar, and photoperiod with environmental cues. It varies between each species such as birds on the equator who can not rely on photoperiods, migratory restlessness will trigger when migratory behavior starts, where the bird will be unable to sit still, and move in the direction of where it wants to migrate

How do birds know where to go for migration? What are some

environmental cues that birds appear to use to help navigate?

Birds use multiple environmental cues and follow their innate genetic template. Some environmental cues birds use to migrate include position of sun in the sky, movement of stars in the night sky, magnetic field of the earth and in some cases, smell (e.g. seabirds with nests) and extreme low-frequency sounds (e.g. of oceans or mountains)

Briefly describe an example of how birds might respond in a

displacement experiment, and what this tells us about their orientation

and navigation, Does experience play a role in a bird’s migration?

young inexperienced birds will follow their original path and end up in the wrong place taken longer paths to finally reach the right place. Experienced adults can correct their path and head toward the original destination, with many birds improving with experience. This tells us their orientation and navigation are genetic, but may change to be more accurate through experience.

How do dispersal, local movements, and migration differ?

Dispersal: is a one-way movement away from a birthing or breeding site, not an annual movement from the same place.

Migration is a yearly two way trip between wintering and breeding sites, happening annually.

Local movements are ones a bird does daily or frequently to find water and food

Describe some categories of ways different groups of birds migrate.

residents: populations of birds that do not migrate

Obligate migrants: classic pattern of predictable twice-annual movements between winter and breeding grounds

Facultative migrants: may or may not migrate, will do “normal” migration some years in years with favorable food supplies, may will stay in their breeding grounds through winter, or may migrate partway

Partial migrant: within one single population, some individuals are obligate migrants, while others are facultative

Leapfrog migration: some populations within a species migrate right past other populations, “leaping” over them.

Nomadic species: move unpredictably according to the availability of food, sometimes breeding at very different times and places between years.

irruptive movements/migrations: mass southward movements of arctic/boreal populations

Explain the roles of staging areas and stopover sites in migration.

Staging areas are where birds will stay at locations for long, multi-day visits to get food resources and fatten up to prepare for starting or continuing their migration

Stopover sites: similar to staging areas, but way shorter visits such as just overnight, or until weather conditions improve.

What is “migratory fallout”?

If unexpected, rapid- onset poor weather creates harsh conditions, massive numbers of

birds can congregate at a stopover site, exhausted.